The present invention relates to an airbag having a vehicle body side panel that is disposed on the side of a vehicle body side and an occupant side panel that is disposed on the side of an occupant at the time of inflation completion, the airbag configured such that the outer peripheral edges of the vehicle body side panel and the occupant side panel are mutually joined and formed into a bag shape, inflation gas made to flow into the airbag from a gas inflow port formed in the vehicle body side panel so as to be able to inflate the airbag, the airbag folded and stored in a storage portion, and the periphery of the gas inflow port installed on the side the storage portion.
As an airbag having this kind of configuration and for use in a steering wheel has been available that is configured such that a crossed belt-shaped regulating member is disposed in an area (an area above a gas inflow port at the time of inflation completion) in the vicinity of a gas inflow port inside the airbag while the four end portions of the regulating member are respectively joined to the side of a vehicle body side panel (for example, refer to JP-A-2009-61970). In this related-art airbag, the external shape of the airbag at the time of inflation completion is regulated by connecting the end portions of the regulating member disposed inside the airbag so as to pull the area of the vehicle body side panel in the vicinity of the gas inflow port inward.
However, in the related-art airbag, since the regulating member is configured so as to be disposed in the vicinity of the gas inflow port inside the airbag, the inflation gas discharged from an inflator is affected by the regulating member so that the inflation gas flows into the airbag in some cases, thereby having a fear of causing a problem in attaining smooth and quick inflation of the airbag.